/*
   *	linux/drivers/video/pmag-aa-fb.c
   *	Copyright 2002 Karsten Merker <merker@debian.org>
   *
   *	PMAG-AA TurboChannel framebuffer card support ... derived from
   *	pmag-ba-fb.c, which is Copyright (C) 1999, 2000, 2001 by
   *	Michael Engel <engel@unix-ag.org>, Karsten Merker <merker@debian.org>
   *	and Harald Koerfgen <hkoerfg@web.de>, which itself is derived from
   *	"HP300 Topcat framebuffer support (derived from macfb of all things)
   *	Phil Blundell <philb@gnu.org> 1998"
   *
   *	This file is subject to the terms and conditions of the GNU General
   *	Public License.  See the file COPYING in the main directory of this
   *	archive for more details.
   *
   *	2002-09-28  Karsten Merker <merker@linuxtag.org>
   *		Version 0.01: First try to get a PMAG-AA running.
   *
   *	2003-02-24  Thiemo Seufer  <seufer@csv.ica.uni-stuttgart.de>
   *		Version 0.02: Major code cleanup.
   *
   *	2003-09-21  Thiemo Seufer  <seufer@csv.ica.uni-stuttgart.de>
   *		Hardware cursor support.
   */
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/timer.h>
  #include <linux/mm.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/fb.h>
  #include <linux/console.h>
  
  #include <asm/bootinfo.h>
  #include <asm/dec/machtype.h>
  #include <asm/dec/tc.h>
  
  #include <video/fbcon.h>
  #include <video/fbcon-cfb8.h>
  
  #include "bt455.h"
  #include "bt431.h"
  
  /* Version information */
  #define DRIVER_VERSION "0.02"
  #define DRIVER_AUTHOR "Karsten Merker <merker@linuxtag.org>"
  #define DRIVER_DESCRIPTION "PMAG-AA Framebuffer Driver"
  
  /* Prototypes */
  static int aafb_set_var(struct fb_var_screeninfo *var, int con,
  			struct fb_info *info);
  
  /*
   * Bt455 RAM DAC register base offset (rel. to TC slot base address).
   */
  #define PMAG_AA_BT455_OFFSET		0x100000
  
  /*
   * Bt431 cursor generator offset (rel. to TC slot base address).
   */
  #define PMAG_AA_BT431_OFFSET		0x180000
  
  /*
   * Begin of PMAG-AA framebuffer memory relative to TC slot address,
   * resolution is 1280x1024x1 (8 bits deep, but only LSB is used).
   */
  #define PMAG_AA_ONBOARD_FBMEM_OFFSET	0x200000
  
  struct aafb_cursor {
  	struct timer_list timer;
  	int enable;
  	int on;
  	int vbl_cnt;
  	int blink_rate;
  	u16 x, y, width, height;
  };
  
  #define CURSOR_TIMER_FREQ	(HZ / 50)
  #define CURSOR_BLINK_RATE	(20)
  #define CURSOR_DRAW_DELAY	(2)
  
  struct aafb_info {
  	struct fb_info info;
  	struct display disp;
  	struct aafb_cursor cursor;
  	struct bt455_regs *bt455;
  	struct bt431_regs *bt431;
  	unsigned long fb_start;
  	unsigned long fb_size;
  	unsigned long fb_line_length;
  };
  
  /*
   * Max 3 TURBOchannel slots -> max 3 PMAG-AA.
   */
  static struct aafb_info my_fb_info[3];
  
  static struct aafb_par {
  } current_par;
  
  static int currcon = -1;
  
  static void aafb_set_cursor(struct aafb_info *info, int on)
  {
  	struct aafb_cursor *c = &info->cursor;
  
  	if (on) {
  		bt431_position_cursor(info->bt431, c->x, c->y);
  		bt431_enable_cursor(info->bt431);
  	} else
  		bt431_erase_cursor(info->bt431);
  }
  
  static void aafbcon_cursor(struct display *disp, int mode, int x, int y)
  {
  	struct aafb_info *info = (struct aafb_info *)disp->fb_info;
  	struct aafb_cursor *c = &info->cursor;
  
  	x *= fontwidth(disp);
  	y *= fontheight(disp);
  
  	if (c->x == x && c->y == y && (mode == CM_ERASE) == !c->enable)
  		return;
  
  	c->enable = 0;
  	if (c->on)
  		aafb_set_cursor(info, 0);
  	c->x = x - disp->var.xoffset;
  	c->y = y - disp->var.yoffset;
  
  	switch (mode) {
  		case CM_ERASE:
  			c->on = 0;
  			break;
  		case CM_DRAW:
  		case CM_MOVE:
  			if (c->on)
  				aafb_set_cursor(info, c->on);
  			else
  				c->vbl_cnt = CURSOR_DRAW_DELAY;
  			c->enable = 1;
  			break;
  	}
  }
  
  static int aafbcon_set_font(struct display *disp, int width, int height)
  {
  	struct aafb_info *info = (struct aafb_info *)disp->fb_info;
  	struct aafb_cursor *c = &info->cursor;
  	u8 fgc = ~attr_bgcol_ec(disp, disp->conp, &info->info);
  
  	if (width > 64 || height > 64 || width < 0 || height < 0)
  		return -EINVAL;
  
  	c->height = height;
  	c->width = width;
  
  	bt431_set_font(info->bt431, fgc, width, height);
  
  	return 1;
  }
  
  static void aafb_cursor_timer_handler(unsigned long data)
  {
  	struct aafb_info *info = (struct aafb_info *)data;
  	struct aafb_cursor *c = &info->cursor;
  
  	if (!c->enable)
  		goto out;
  
  	if (c->vbl_cnt && --c->vbl_cnt == 0) {
  		c->on ^= 1;
  		aafb_set_cursor(info, c->on);
  		c->vbl_cnt = c->blink_rate;
  	}
  
  out:
  	c->timer.expires = jiffies + CURSOR_TIMER_FREQ;
  	add_timer(&c->timer);
  }
  
  static void __init aafb_cursor_init(struct aafb_info *info)
  {
  	struct aafb_cursor *c = &info->cursor;
  
  	c->enable = 1;
  	c->on = 1;
  	c->x = c->y = 0;
  	c->width = c->height = 0;
  	c->vbl_cnt = CURSOR_DRAW_DELAY;
  	c->blink_rate = CURSOR_BLINK_RATE;
  
  	init_timer(&c->timer);
  	c->timer.data = (unsigned long)info;
  	c->timer.function = aafb_cursor_timer_handler;
  	mod_timer(&c->timer, jiffies + CURSOR_TIMER_FREQ);
  }
  
  static void __exit aafb_cursor_exit(struct aafb_info *info)
  {
  	struct aafb_cursor *c = &info->cursor;
  
  	del_timer_sync(&c->timer);
  }
  
  static struct display_switch aafb_switch8 = {
  	.setup = fbcon_cfb8_setup,
  	.bmove = fbcon_cfb8_bmove,
  	.clear = fbcon_cfb8_clear,
  	.putc = fbcon_cfb8_putc,
  	.putcs = fbcon_cfb8_putcs,
  	.revc = fbcon_cfb8_revc,
  	.cursor = aafbcon_cursor,
  	.set_font = aafbcon_set_font,
  	.clear_margins = fbcon_cfb8_clear_margins,
  	.fontwidthmask = FONTWIDTH(4)|FONTWIDTH(8)|FONTWIDTH(12)|FONTWIDTH(16)
  };
  
  static void aafb_get_par(struct aafb_par *par)
  {
  	*par = current_par;
  }
  
  static int aafb_get_fix(struct fb_fix_screeninfo *fix, int con,
  			struct fb_info *info)
  {
  	struct aafb_info *ip = (struct aafb_info *)info;
  
  	memset(fix, 0, sizeof(struct fb_fix_screeninfo));
  	strcpy(fix->id, "PMAG-AA");
  	fix->smem_start = ip->fb_start;
  	fix->smem_len = ip->fb_size;
  	fix->type = FB_TYPE_PACKED_PIXELS;
  	fix->ypanstep = 1;
  	fix->ywrapstep = 1;
  	fix->visual = FB_VISUAL_MONO10;
  	fix->line_length = 1280;
  	fix->accel = FB_ACCEL_NONE;
  
  	return 0;
  }
  
  static void aafb_set_disp(struct display *disp, int con,
  			  struct aafb_info *info)
  {
  	struct fb_fix_screeninfo fix;
  
  	disp->fb_info = &info->info;
  	aafb_set_var(&disp->var, con, &info->info);
  	if (disp->conp && disp->conp->vc_sw && disp->conp->vc_sw->con_cursor)
  		disp->conp->vc_sw->con_cursor(disp->conp, CM_ERASE);
  	disp->dispsw = &aafb_switch8;
  	disp->dispsw_data = 0;
  
  	aafb_get_fix(&fix, con, &info->info);
  	disp->screen_base = (u8 *) fix.smem_start;
  	disp->visual = fix.visual;
  	disp->type = fix.type;
  	disp->type_aux = fix.type_aux;
  	disp->ypanstep = fix.ypanstep;
  	disp->ywrapstep = fix.ywrapstep;
  	disp->line_length = fix.line_length;
  	disp->next_line = 2048;
  	disp->can_soft_blank = 1;
  	disp->inverse = 0;
  	disp->scrollmode = SCROLL_YREDRAW;
  
  	aafbcon_set_font(disp, fontwidth(disp), fontheight(disp));
  }
  
  static int aafb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
  			 struct fb_info *info)
  {
  	static u16 color[2] = {0x0000, 0x000f};
  	static struct fb_cmap aafb_cmap = {0, 2, color, color, color, NULL};
  
  	fb_copy_cmap(&aafb_cmap, cmap, kspc ? 0 : 2);
  	return 0;
  }
  
  static int aafb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
  			 struct fb_info *info)
  {
  	u16 color[2] = {0x0000, 0x000f};
  
  	if (cmap->start == 0
  	    && cmap->len == 2
  	    && memcmp(cmap->red, color, sizeof(color)) == 0
  	    && memcmp(cmap->green, color, sizeof(color)) == 0
  	    && memcmp(cmap->blue, color, sizeof(color)) == 0
  	    && cmap->transp == NULL)
  		return 0;
  	else
  		return -EINVAL;
  }
  
  static int aafb_ioctl(struct fb_info *info, u32 cmd, unsigned long arg)
  {
  	/* TODO: Not yet implemented */
  	return -ENOIOCTLCMD;
  }
  
  static int aafb_switch(int con, struct fb_info *info)
  {
  	struct aafb_info *ip = (struct aafb_info *)info;
  	struct display *old = (currcon < 0) ? &ip->disp : (fb_display + currcon);
  	struct display *new = (con < 0) ? &ip->disp : (fb_display + con);
  
  	if (old->conp && old->conp->vc_sw && old->conp->vc_sw->con_cursor)
  		old->conp->vc_sw->con_cursor(old->conp, CM_ERASE);
  
  	/* Set the current console. */
  	currcon = con;
  	aafb_set_disp(new, con, ip);
  
  	return 0;
  }
  
  static void aafb_encode_var(struct fb_var_screeninfo *var,
  			    struct aafb_par *par)
  {
  	var->xres = 1280;
  	var->yres = 1024;
  	var->xres_virtual = 2048;
  	var->yres_virtual = 1024;
  	var->xoffset = 0;
  	var->yoffset = 0;
  	var->bits_per_pixel = 8;
  	var->grayscale = 1;
  	var->red.offset = 0;
  	var->red.length = 0;
  	var->red.msb_right = 0;
  	var->green.offset = 0;
  	var->green.length = 1;
  	var->green.msb_right = 0;
  	var->blue.offset = 0;
  	var->blue.length = 0;
  	var->blue.msb_right = 0;
  	var->transp.offset = 0;
  	var->transp.length = 0;
  	var->transp.msb_right = 0;
  	var->nonstd = 0;
  	var->activate &= ~FB_ACTIVATE_MASK & FB_ACTIVATE_NOW;
  	var->accel_flags = 0;
  	var->sync = FB_SYNC_ON_GREEN;
  	var->vmode &= ~FB_VMODE_MASK & FB_VMODE_NONINTERLACED;
  }
  
  static int aafb_get_var(struct fb_var_screeninfo *var, int con,
  			struct fb_info *info)
  {
  	if (con < 0) {
  		struct aafb_par par;
  
  		memset(var, 0, sizeof(struct fb_var_screeninfo));
  		aafb_get_par(&par);
  		aafb_encode_var(var, &par);
  	} else
  		*var = info->var;
  
  	return 0;
  }
  
  static int aafb_set_var(struct fb_var_screeninfo *var, int con,
  			struct fb_info *info)
  {
  	struct aafb_par par;
  
  	aafb_get_par(&par);
  	aafb_encode_var(var, &par);
  	info->var = *var;
  
  	return 0;
  }
  
  static int aafb_update_var(int con, struct fb_info *info)
  {
  	struct aafb_info *ip = (struct aafb_info *)info;
  	struct display *disp = (con < 0) ? &ip->disp : (fb_display + con);
  
  	if (con == currcon)
  		aafbcon_cursor(disp, CM_ERASE, ip->cursor.x, ip->cursor.y);
  
  	return 0;
  }
  
  /* 0 unblanks, any other blanks. */
  
  static void aafb_blank(int blank, struct fb_info *info)
  {
  	struct aafb_info *ip = (struct aafb_info *)info;
  	u8 val = blank ? 0x00 : 0x0f;
  
  	bt455_write_cmap_entry(ip->bt455, 1, val, val, val);
  	aafbcon_cursor(&ip->disp, CM_ERASE, ip->cursor.x, ip->cursor.y);
  }
  
  static struct fb_ops aafb_ops = {
  	.owner = THIS_MODULE,
  	.fb_get_fix = aafb_get_fix,
  	.fb_get_var = aafb_get_var,
  	.fb_set_var = aafb_set_var,
  	.fb_get_cmap = aafb_get_cmap,
  	.fb_set_cmap = aafb_set_cmap,
  	.fb_ioctl = aafb_ioctl
  };
  
  static int __init init_one(int slot)
  {
  	unsigned long base_addr = CKSEG1ADDR(get_tc_base_addr(slot));
  	struct aafb_info *ip = &my_fb_info[slot];
  
  	memset(ip, 0, sizeof(struct aafb_info));
  
  	/*
  	 * Framebuffer display memory base address and friends.
  	 */
  	ip->bt455 = (struct bt455_regs *) (base_addr + PMAG_AA_BT455_OFFSET);
  	ip->bt431 = (struct bt431_regs *) (base_addr + PMAG_AA_BT431_OFFSET);
  	ip->fb_start = base_addr + PMAG_AA_ONBOARD_FBMEM_OFFSET;
  	ip->fb_size = 2048 * 1024; /* fb_fix_screeninfo.smem_length
  				      seems to be physical */
  	ip->fb_line_length = 2048;
  
  	/*
  	 * Let there be consoles..
  	 */
  	strcpy(ip->info.modename, "PMAG-AA");
  	ip->info.node = -1;
  	ip->info.flags = FBINFO_FLAG_DEFAULT;
  	ip->info.fbops = &aafb_ops;
  	ip->info.disp = &ip->disp;
  	ip->info.changevar = NULL;
  	ip->info.switch_con = &aafb_switch;
  	ip->info.updatevar = &aafb_update_var;
  	ip->info.blank = &aafb_blank;
  
  	aafb_set_disp(&ip->disp, currcon, ip);
  
  	/*
  	 * Configure the RAM DACs.
  	 */
  	bt455_erase_cursor(ip->bt455);
  
  	/* Init colormap. */
  	bt455_write_cmap_entry(ip->bt455, 0, 0x00, 0x00, 0x00);
  	bt455_write_cmap_entry(ip->bt455, 1, 0x0f, 0x0f, 0x0f);
  
  	/* Init hardware cursor. */
  	bt431_init_cursor(ip->bt431);
  	aafb_cursor_init(ip);
  
  	/* Clear the screen. */
  	memset ((void *)ip->fb_start, 0, ip->fb_size);
  
  	if (register_framebuffer(&ip->info) < 0)
  		return -EINVAL;
  
  	printk(KERN_INFO "fb%d: %s frame buffer in TC slot %d
  ",
  	       GET_FB_IDX(ip->info.node), ip->info.modename, slot);
  
  	return 0;
  }
  
  static int __exit exit_one(int slot)
  {
  	struct aafb_info *ip = &my_fb_info[slot];
  
  	if (unregister_framebuffer(&ip->info) < 0)
  		return -EINVAL;
  
  	return 0;
  }
  
  /*
   * Initialise the framebuffer.
   */
  int __init pmagaafb_init(void)
  {
  	int sid;
  	int found = 0;
  
  	while ((sid = search_tc_card("PMAG-AA")) >= 0) {
  		found = 1;
  		claim_tc_card(sid);
  		init_one(sid);
  	}
  
  	return found ? 0 : -ENXIO;
  }
  
  static void __exit pmagaafb_exit(void)
  {
  	int sid;
  
  	while ((sid = search_tc_card("PMAG-AA")) >= 0) {
  		exit_one(sid);
  		release_tc_card(sid);
  	}
  }
  
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
  MODULE_LICENSE("GPL");
  #ifdef MODULE
  module_init(pmagaafb_init);
  module_exit(pmagaafb_exit);
  #endif